The instant invention relates to electrical switches and more particularly to a water-resistant electrical switch which is adapted for use in connection with small appliances, such as hair dryers and the like.
It has generally been found that each year a significant number of deaths are caused by electrocution when of small appliances, such as hair dryers and the like, are inadvertently dropped into bathtubs or sinks which are filled or partially filled with water. More specifically, it has been found that a significant number of deaths result from short circuiting in the switches of small appliances of this general type when the appliances are immersed in water. In this connection, most of the heretofore available switches for appliances of this general type have not been adapted for water-resistant constructions, and they have generally been susceptible to short circuiting regardless of whether they are in "on" or "off" positions. Hence, many of the heretofore available small appliances, such as hair dryers and the like, have generally presented relatively serious health hazards. Recently, however, an increased awareness of the need to eliminate such health hazards has developed, and as a result a significant need has developed for an effective and economical water-resistant switch construction for small appliances, such as those which are frequently utilized in bathroom areas.
The instant invention provides an effective and economical water-resistant switch construction which is highly resistant to moisture penetration and which is adapted for relatively inexpensive constructions so that it can be effectively utilized in a variety of small appliances, such as hair dryers and the like. More specifically, the instant invention provides a switch construction of the general type comprising a housing including first and second molded plastic housing sections, fixed and movable contacts in the housing, first and second electrical terminals electrically connected in sealed relation to the fixed and movable contacts and a actuator which is pivotably mounted in the housing. The actuator includes an actuator arm which passes through an aperture in the first housing section, and the actuator arm is manipulatable from the exterior of the housing for pivoting the actuator to move the movable contact between a first position wherein it is in engagement with the fixed contact and a second position wherein it is in spaced disengagement from the fixed contact. However, the improvement in the switch construction of the instant invention resides in the fact that it is effectively adapted to resist moisture penetration so that it can be effectively utilized in connection with small appliances, such as those which are intended for bathroom use. Specifically, the switch construction of the instant invention further comprises an O-ring seal which is mounted in the interior of the first housing section so that it extends around the aperture therein, and the actuator includes a substantially hemispherical portion. The actuator is constructed so that the actuator arm extends outwardly from the substantially hemispherical portion, and the actuator is assembled in the switch so that the surface of the subtantially hemispherical portion engages the O-ring to provide a seal between the actuator and the first housing section. The actuator is further assembled in the switch so that the actuator arm passes through the O-ring and then extends outwardly through the aperture in the first housing section. Accordingly, when the actuator arm is manipulated to move the movable contact, the O-ring passes in sealed relation over the surface of the substantially hemispherical portion of the actuator as the actuator is pivoted in the housing. The substantially hemispherical portion of the actuator is preferably made from a low-friction polymer, such as nylon, to enable the Oring to effectively pass over the surface thereof with a minimum of frictional resistance as the actuator is pivoted in the housing, and the first and second housing sections of the switch are preferably ultrasonically sealed together to provide an effective watertight seal therebetween. The first housing section preferably has a substantially circular seat formed therein which extends around the aperture in the first housing section, and the O-ring is preferably received in sealed relation in the seat. Further, the actuator of the switch preferably comprises a spring-biased plunger element which is engageable with the movable contact for moving the movable contact between a first position wherein it is in engagement with the fixed contact and a second position wherein it is in spaced disengagement from the fixed contact. Still further, the switch construction of the instant invention is effectively adapted so that it can be embodied in a variety of different types of water-resistant switches for various specific applications. In particular, the switch construction of the instant invention is adapted so that it can be effectively embodied as a single-pole, single-throw switch; as a single-pole, double-throw switch; as a double-pole, single-throw switch; or as a double-pole, double-throw switch, depending on the intended use. Accordingly, the switch construction of the subject invention may include one or more fixed and/or movable contacts, depending on the specific embodiment.
It has been found that the switch construction of the instant invention can be effectively utilized in connection with various small appliances, such as hair dryers and the like, in order to substantially reduce the hazards which have been heretofore associated with utilizing such appliances in bathroom environments. Specifically, the O-ring seal and the substantially hemispherical portion of the actuator of the switch cooperate to provide an effective seal between the actuator and the housing while nevertheless allowing the actuator to be easily manipulated from the exterior of the housing. Further, the ultrasonic seal between the first and second housing sections effectively eliminates moisture penetration through the housing where the first and second housing sections are joined. Still further, the relative simplicity of the structural features of the switch construction which contribute to substantially reducing the potential for moisture penetration make the switch construction of the instant invention effectively adapted for a variety of relatively inexpensive constructions.
Accordingly, it is a primary object of the instant invention to provide an effective water-resistant switch construction for use in connection with small appliances.
Another object of the instant invention is to provide an economical water-resistant switch construction.
An even further object of the instant invention is to provide an effective water-resistant switch construction which is adapted to be embodied in a variety of different types of switches for various different specific applications.
Other objects, features and advantages of the invention shall become apparant as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.